'Tension setting' is believed to have been started in Europe, possibly Germany, about 30 years ago. In tension set rings, the stone is held in place only by 'tension' of the metal band. Initially gold and silver were used in the manufacturing. However as gold and silver are relatively soft material and in order to achieve the required 'tension', the bands had to be made fairly thick, resulting in a chunky and heavy ring.
Today, you will find tension set rings using platinum, gold, stainless steel and titanium. The tension has to be just right, if it is too loose the stone will fall out and if too tight the stone will crack. With tension setting, light is allowed to pass through the stone unimpeded resulting in a more brilliant stone. Tension setting also allows a flatter profile for a high tech look. Due to the way the ring is made, the ring generally cannot be resized. Each our tension set ring is engineered to exacting specifications with a seat cut into the side to hold the stone and a carefully calculated gap for the size stone selected for that design. Every style is engineered to maximize the security of the setting.